The field of communications has become increasingly important in today's society. In particular, the ability to quickly and effectively interact with an individual (through any suitable communications media) presents a significant obstacle for component manufacturers, system designers, and network operators. This obstacle is made even more difficult due to the plethora of diverse communication technologies (e.g. Instant Messaging, cellular communications, simple voice sessions, etc.) that exist in the current marketplace.
As new communication platforms (such as session initiation protocol (SIP), for example) become available to the consumer, new protocols need to be developed in order to optimize this emerging technology. For example, one problem often encountered by a caller in any communications environment is being unable to reach a callee because the callee is not available. The called party may be unavailable for the call for any number of reasons. For example, the called party may be out of the office, on another line, e-mailing another party, preparing a document, talking on their cellular telephone, etc. The calling party is generally oblivious to this information, as he has no idea how to effectively contact this person. In some situations where the callee is busy, the caller can leave a simple voicemail or send them an e-mail (i.e. facilitate the phone-tag scenario). However, in some instances, a live discussion is necessary, whereby an interactive session should be accommodated.
This lack of knowledge and lack of interaction wastes valuable time, frustrates both parties, causes delays in communications, and inhibits productivity. Accordingly, this problem is a burden for any employee, employer, individual, or endpoint that seeks to execute a successful and productive communication session.
eCamp-On is generally a private branch exchange (PBX) feature. In an eCamp-On™ scenario, a calling party calls the called party whose phone is busy. The calling then party camps on the called party's phone and is called back when the (busy) called party phone becomes available. Cellular and Internet Protocol (IP) phones provide the user with a means of obtaining the number of callers whose calls have been missed. The called party can search the directory, select a number, and place a call. Lacking in such an environment is a feature that allows the (busy) called party to Camp-On the calling party and to invoke a call from the called party's phone to the calling party's phone.